Anatomical Changes. 107 



The abdominal cavity sometimes contains several liters of 

 a yellowisli or reddisli serous fluid. The small intestine mani- 

 fests lesions of a pronounced acute hemorrhagic inflamma- 

 tion, which while also present in the large intestine are less 

 marked there. The content of the intestinal canal is thin, 

 fluid, yellowish-gray, or from an admixture of 1)lood, dirty- 

 reddish in color. The spleen is normal, or at most in parts, 

 somewhat swollen. The blood is also normal in color. 



In the pectoral form the thoracic cavity contains serous 

 or sero-fibrinous exudate which is sometimes mixed with blood. 

 The pleura is inflamed and studded with small hemorrhages, 

 especially the visceral layer which appears to be covered with 

 fibrinous membranes. In one or both lungs smaller or larger 

 connecting parts are hepatized and friable. The cut surfaces 

 are uniformly dark, brownish or reddisli in color, finely grai> 

 ular, and contain, in less acute cases, small, dry, caseous areas. 

 Sometimes the interlobular connective tissue septa appear 

 thickened and yellowish-white through serous infiltration, so 

 that the cut surface of the lung has a mottled marbled appear- 

 ance (the appearance in such cases is very similar to the lungs 

 in contagious pleuro-pneumonia [Fig. 27]). The parts which 

 are not hepatized show marked hyperemia and edema. The 

 pericardium may also contain an exudate mixed with fibrinous 

 flakes. The connective tissue of the mediastinum is gelatinously 

 infiltrated and studded with hemorrhages. The peribronchial 

 lymph glands are acutely swollen; usually there is also an 

 acute enteritis present, while the spleen preserves a normal 

 appearance even in severe cases. 



Nocard, who diagnosed the disease in cattle imported from America 

 to Paris, (broncho-pneumonia of American cattle) emphasizes the fact 

 that the serous fluid in the lungs differs from that of contagious pleuro- 

 pneumonia. It is not so markedly yellow, and has not the appearance 

 of lymph, also the thickened lymph spaces are filled with a whitish, 

 tenaceous, fibrinous coagulum. The individual lobules appear firmer in 

 the center and more markedly hepatized than in the periphery, which 

 is probably on account of the fact that the inflammatory process 

 extends from the bronchi and not from the interlobular connective 

 tissue. 



According to the anatomical findings in the different cases, Bollinger 

 distinguished a pectoral and an exanthematous form of the disease, 

 the former occurring principally in Adld animals, while the latter is 

 supposed to be more frequent in cattle. Later a so-called intestinal 

 form was also described, which, however, does not occur independently, 

 but only in association with one of the previously mentioned forms (the 

 designation "exanthematous form" is not appropriate as there is 

 no exanthema present but only an inflammatory edema). 



Symptoms. The time of incubation of the disease in inocu- 

 lation and feeding experiments proved to be from 6 to 24 hours. 

 In natural infections it is probably somewhat longer, but it 

 hardly ever extends over 2 days. 



